The ASO antibody may be found in the blood weeks or months after the strep infection has gone away.

Normal Values

A negative test result means you have likely not had a recent strep infection. The healthcare provider may repeat the test again in 2 - 4 weeks. Sometimes a test that was first negative will come back positive.

Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What abnormal results mean

An abnormal or positive test means you recently had a strep infection, even if you had no symptoms.
The ASO test may stay positive (sometimes called detectable) for 2 to 4 months afterward you are first infected.

What the risks are

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include: